Self-locking strap buckle

ABSTRACT

It has been found that buckles made of metal for us with plastic or cloth web strapping material fail because the arms of the buckles bend under the stress of the web. A buckle is disclosed herein which does not bend under normal strapping stresses. This is achieved by welding one of the four parallel arms rigidly to the body of the buckle to constrain the buckle from bending.

United States Patent Somann [451 May 23, 1972 [54] SELF-LOCKING STRAP BUCKLE FOREIGN PATENTS OR APPLICATIONS Inventor; Gert so -nan Huron Park ()nt ario Australia Canada Primary Examiner-Bobby R. Gay [73] Assrgnee: Ferplas Industries Limited, Huron Park, Assistant Mom-e Ontano, Canada AttomeyPhilip T. Mitches 22 F'] d: A 2 1970 1 1e P i 57 ABSTRACT I A N 2 8 1 P1 9 5,0 3 It has been found that buckles made of metal for us with plastic or cloth web strapping material fail because the arms of [30] Foreign Application Priority Data the buckles bend under the stress of the web.

Apr. 2, 1969 Canada ..047577 A buckle is disclosed herein which does not bend under normal strapping stresses. This is achieved by welding one of the [52] US. Cl ..24/74, 24/16 four parallel arms rigidly to the body of the buckle to con- [51 Int. Cl. strain the buckle from bending. [58] Field of Search ..24/74, 26, 16

4 Claim, 6 Drawing Figures [56] References Cited UNITED STATES PATENTS 3,377,666 4/1968 Sherman ..24/74 3,! l2.543 12/ I963 Derrickson ..24/74 r 6 L 33 30 i Patented May 23', 1972 3,663,995

PHILIP l/TCHEj This invention relates to an improved connector or buckle for securing the opposite ends of a flexible strap loop which is arranged in taut relation about a package, bail, box or bundle or other object that is to be tied.

With the advent and subsequent popularity of non-metallic strapping such as nylon, polypropylene, rayon and the like, whether in rope or cord configuration, or band or strap configuration, they brought about a demand for specialized fasteners or buckles for securing and tensioning the opposite ends, particularly of strap loops, by means of frictional engagement rather than by means of strapping and sealing tools.

As a result two types of fasteners or buckles have emerged for non-metallic strapping; those made from a rigid or semirigid molded plastic material and those made from spring wire steel. Both types have serious limitations which have unduly limited the full exploitation of the unique advantages of plastic strapping over steel strapping.

Referring to U.S. Pat. No. 3,206,816 issued Sept. 21, 1965 to I. J. Vilcins, a light packing strap buckle composed of plastic is disclosed which, under heavy tension distorts and causes subsequent failure of the plastic material. Stronger tortion free plastics composed of polycarbonate are not economical to make for these applications.

Referring to U.S. Pat. No. 3,014,256 issued Dec. 26, 1961 to M. O. Derrickson and in U.S. Pat. No. 3,349,444 issued Oct. 31, 1967 to J. R. Beach a buckle is disclosed composed of a single length of steel wire appropriately shaped. It has been found, that buckles made in accordance with these inventions, distort under heavy tension well below the breaking point of the plastic strapping being used. This distortion is of such nature that it destroys the parallel arrangement between the pairs of strap engaging arms at the opposite ends of the buckle and thus reduces the frictional hold which the buckle has on the plastic strapping to cause slipping and hence loosening of the strapping about the package or object which is to be tied.

This asymmetrical distortion is caused by the fact that one side of the buckle is formed from a length of wire which has one or two bends hile the opposite side is formed from a straight length of wire. Under the heavy tension, the rectangular shape of such buckle distorts tending to straighten out the bends which compose the buckle. This in turn destroys, as we have noted, the parallel arrangement of the two pairs of strap engaging arms at opposite ends of the buckle.

It has been found, that the parallelism of the strap engaging arms can be maintained, irrespective of the tension whereby excellent holding properties of the buckle are achieved, if the buckle itself is made rigid.

The invention therefore contemplates a buckle for use in connection with flexible strapping comprising a single piece of wire formed as follows:

a. First generally U shaped portion including a distal leg formed from one end of said single piece of wire, a proximal leg and a bight;

b. A second generally U shaped portion including a distal leg formed from the other end of said single piece of wire, a proximal leg, and bight;

c. An intermediate wire portion connecting the proximal legs of each U shaped portion; said two proximal legs and said intermediate wire portion lying in a plane having essentially a U shaped configuration; said two distal legs lying parallel to each other as well as parallel to said proximal legs, the ends of said distal legs extending across the intennediate wire portion;

each proximate leg of the first and second generally U shaped portions connected to the intermediate wire portion at obtuse angles and wherein said proximate legs are disposed in one plane said distal legs disposed in another plane, both planes being coplanar; and

d. Connection means securing the overlying bights on the buckle to hold the proximate legs in parallel relationship.

The invention will now be described by way of example reference being had to the accompanying drawings in which;

FIG. 1 is a plan view of one embodiment of the connector;

FIG. 2 is a side elevation view showing a strap in process of being laced with a connector;

FIG. 3 is an end view of the embodiment of FIG. 1;

FIG. 4 is a plan view of yet another embodiment of the invention;

FIG. 5 is a perspective view showing one manner of tightening a strap about a package when using the connector of FIG.

FIG. 6 is a section along line 6 6 of FIG. 4.

Referring to FIG. 1 and one embodiment of the invention, a buckle 10 includes a first generally U shaped portion 11 with distal leg 12, proximate leg 13, and bight 14; a second generally U shaped portion 15 including a distal leg 16, proximal leg 17, and bight 18. An intermediate wire portion 19 connects the proximate legs 13 and 17 into a U shaped planar portion. The distal legs may be held in parallel relationship as by welding 20, the end portion of distal leg 16 to intermediate wire portion 19.

Referring to FIG. 4 and another embodiment of the invention, a buckle 30 is constructed in a like manner to that of buckle l0. Particularly, the buckle 30 includes a first generally U shaped portion 31 with distal leg 32, proximate leg 33, and bight 34; a secondly U shaped portion 35 including a distal leg 36, proximate leg 37, and bight 38. Particularly, the first and second generally U shaped portions, 31 and 35 are distorted as more particularly seen. As a result, an intermediate wire portion 39 which connects the proximate leg 33 and 37 is bent in an obtuse form to create a likewise distorted U shaped planar portion consisting of the intermediate wire portion 39, and proximate legs 33 and 37. Distal legs 36 and 32 are parallel and co-planar one with respect to the other and this arrangement is maintained by making each U shaped portion 31 and 35 rigid with respect to one another as by affixing the overlap of bight 38 with bight 34 to one another as by a weld or other securing means 40.

Now referring to buckle l0 and to FIG. 2 a plastic strap 50 may be secured to the buckle in the following manner.

The free end 51 of the strap is thread over a distal leg 12 and thence between the distal leg 12 and the adjacent proximate leg 17 thence beneath and around the proximate leg I7 to overlie the strap 50. This is more clearly seen in the right hand portion of FIG. 3 wherein the strap is shown in its loose" position around the distal leg 12. The end of the strap should extend at least one inch beyond the buckle 10 in order to provide sufficient free strap should there be any giving of the buckle and strap during tightening (refer to FIG. 5). The other end of the strap 50 after having looped about a package 53 which is to be tied, is threaded over the other proximate arm 13 and thence between that proximate arm 13 and its adjacent distal leg 16 as more particularly shown in the left hand portion of FIG. 3.

Tightening can be accommodated as shown in FIG. 5 by pulling the taut end 58 of the strap to make the strap 50 snug.

Referring particularly to FIG. 3, it will be noted, that with respect to buckle 10, the proximate leg 13 is disposed from the distal leg 16 to a greater extent than the distal leg 12 is disposed from the proximate leg 17. The greater disposition of the proximate leg 13, insures greater frictional engagement of strap 50 about the distal leg 16 because the strap regions 54 and 55 are in abutting relationship and wrapped about the distal leg 16 to a greater extent than they otherwise would if the proximate leg 13 did not overlie the distal leg 16 so much. On the other hand, in order to assist the tightening of the strap 50 about the package 53, the distal leg 12 overlies the proximate leg 17 by only a relatively small amount. This insures that the strap region 56 and 57 which are abutting, only wrap about the proximate leg 17 approximately one quarter of the circumference of the proximate leg 17. This is sufficient to give good frictional contact between regions 56 and 57, and yet allow tightening of the strap 50 by hand (FIG. 5).

In view of the fact that the distal leg 12 is not welded to the intermediate portion 19, this permits a looping of the strap 50 to be made and the eye 59 of the loop to be passed over the open end of the distal leg 12 and capable of being pulled taut as by the hand 61 (FIG. 5).

If the distal leg 12 were welded to the intermediate wire portion 19, the strap 50 would have to be cut from the spool 62 and threaded through the space between abutting distal leg 12 and proximate leg 17 in a like manner as the free end 51 is threaded about proximate leg 13 and between proximate leg 13 and distal leg 16 as earlier described.

Referring to FIG. 6 and to FIG. 4, both distal legs 36 and 32 are subjacent to the proximate legs 33 and 37 and thereby provides similar frictional engaging characteristics as that of the respective legs of buckle however, on careful examination of FIGS. 4 and 6 it will be seen that the distal legs 36 and 32 of buckle 30 are what may be considered the load bearing legs, while the buckle 10 of FIGS. 1 and 3, the load bearing legs consist of the distal leg 12 and the proximate leg 13.

The embodiments of the invention in which an exclusive property and privilege are claimed are defined as follows:

1. A buckle for use in connection with flexible strapping comprising a single piece of wire formed as follows:

a. First generally U shaped portion including a distal leg formed from one end of said single piece of wire, a proximal leg and a bight;

b. A second generally U shaped portion including a distal leg formed from the other end of said single piece of wire,

a proximal leg, and bight;

c. An intermediate wire portion connecting the proximal legs of each U shaped portion; said two proximal legs and said intermediate wire portion lying in a plane having essentially a U shaped configuration; said two distal legs lying parallel to each other as well as parallel to said proximal legs, the ends of said distal legs extending across the intermediate wire portion; each proximate leg of the first and second generally U shaped portions connected to the intermediate wire portion at obtuse angles and wherein said proximate legs are disposed in one plane said distal legs disposed in another plane, both planes being coplanar; and

d. Securing means fixedly connecting the overlying bights on the buckle to hold the proximate legs in parallel relationship.

2. The buckle of claim 1 wherein the securing means (d) is a spot weld.

3. The buckle of claim 1 wherein the distal legs are superadjacent to and disposed relatively closer to each other than the proximate legs.

4. The buckle of claim 2 wherein the distal legs are superadjacent to and disposed relatively closer to each other than the proximate legs. 

1. A buckle for use in connection with flexible strapping comprising a single piece of wire formed as follows: a. First generally U shaped portion including a distal leg formed from one end of said single piece of wire, a proximal leg and a bight; b. A second generally U shaped portion including a distal leg formed from the other end of said single piece of wire, a proximal leg, and bight; c. An intermediate wire portion connecting the proximal legs of each U shaped portion; said two proximal legs and said intermediate wire portion lying in a plane having essentially a U shaped configuration; said two distal legs lying parallel to each other as well as parallel to said proximal legs, the ends of said distal legs extending across the intermediate wire portion; each proximate leg of the first and second generally U shaped portions connected to the intermediate wire portion at obtuse angles and wherein said proximate legs are disposed in one plane said distal legs disposed in another plane, both planes being co-planar; and d. Securing means fixedly connecting the overlying bights on the buckle to hold the proximate legs in parallel relationship.
 2. The buckle of claim 1 wherein the securing means (d) is a spot weld.
 3. The buckle of claim 1 wherein the distal legs are superadjacent to and disposed relatively closer to each other than the proximate legs.
 4. The buckle of claim 2 wherein the distal legs are superadjacent to and disposed relatively closer to each other than the proximate legs. 